Apparatus for moving seat rail for vehicle

Abstract

An apparatus for moving a seat rail for a vehicle includes a casing, a lead nut mounted in the casing, screw-coupled to a lead screw configured to penetrate the casing, and configured to move along the lead screw, a worm wheel coupled to an outer-diameter portion of the lead nut, a locking member provided between the outer-diameter portion of the lead nut and an inner-diameter portion of the worm wheel, and a clutch drum coupled to one side outer-diameter portion of the lead nut so as to be opposite to the worm wheel and configured to perform an engagement operation to release a locked state of the locking member and prevent power from the worm wheel from being transmitted to the lead nut.

What is claimed is: 
     
         1 . An apparatus for moving a seat rail for a vehicle, the apparatus comprising:
 a casing;   a lead nut mounted in the casing and configured to be screw-coupled to a lead screw penetrating the casing and move along the lead screw;   a worm wheel coupled to an outer-diameter portion of the lead nut;   at least one locking member disposed between the outer-diameter portion of the lead nut and an inner-diameter portion of the worm wheel; and   a clutch drum coupled to one side of the outer-diameter portion of the lead nut and facing the worm wheel, the clutch drum being configured to perform an engagement operation to release a locked state of the at least one locking member and prevent power from the worm wheel from being transmitted to the lead nut.   
     
     
         2 . The apparatus of  claim 1 ,
 wherein the at least one locking member comprises:   a first locking member and a second locking member disposed on one side of the inner-diameter portion of the worm wheel; and   a third locking member and a fourth locking member disposed on another side of the inner-diameter portion of the worm wheel, and   wherein the clutch drum comprises:   a first coupling protrusion and a second coupling protrusion positioned on one surface of the clutch drum directed toward the worm wheel; and   at least one key positioned on an inner-diameter portion of the clutch drum and coupled to at least one key groove defined on the outer-diameter portion of the lead nut in a longitudinal direction of the lead nut, the at least one key being slidable along the at least one key groove.   
     
     
         3 . The apparatus of  claim 2 , wherein a support member is disposed between the worm wheel and the clutch drum, a first support protrusion and a second support protrusion are positioned on one surface of the support member and inserted into the inner-diameter portion of the worm wheel, and a first support surface, a second support surface, a third support surface, and a fourth support surface are positioned on the outer-diameter portion of the lead nut along a circumferential direction of the lead nut. 
     
     
         4 . The apparatus of  claim 3 ,
 wherein the first locking member comprises:   a first elastic body having one end supported by the first support protrusion on the one side of the inner-diameter portion of the worm wheel; and   a first roller disposed at another end of the first elastic body opposite to the one end of the first elastic body, configured to be pushed by an elastic force of the first elastic body, and configured to be fitted between the inner-diameter portion of the worm wheel and one end of the first support surface such that the worm wheel and the lead nut are integrally rotatable,   wherein the second locking member comprises:   a second elastic body disposed opposite to the first elastic body on the one side of the inner-diameter portion of the worm wheel and having one end supported by the second support protrusion; and   a second roller disposed opposite to the first roller on the one side of the inner-diameter portion of the worm wheel, the second roller being configured to be pushed by an elastic force of the second elastic body and configured to be fitted between the inner-diameter portion of the worm wheel and one end of the second support surface such that the worm wheel and the lead nut are integrally rotatable,   wherein the third locking member comprises:   a third elastic body having one end supported by the first support protrusion on the another side of the inner-diameter portion of the worm wheel; and   a third roller disposed at another end of the third elastic body opposite to the one end of the third elastic body, configured to be pushed by an elastic force of the third elastic body, and configured to be fitted between the inner-diameter portion of the worm wheel and one end of the third support surface such that the worm wheel and the lead nut are integrally rotatable, and   wherein the fourth locking member comprises:   a fourth elastic body disposed opposite to the third elastic body on the another side of the inner-diameter portion of the worm wheel and having one end supported by the second support protrusion; and   a fourth roller disposed opposite to the third roller on the another side of the inner-diameter portion of the worm wheel, the fourth roller being configured to be pushed by an elastic force of the fourth elastic body and configured to be fitted between the inner-diameter portion of the worm wheel and one end of the fourth support surface such that the worm wheel and the lead nut are integrally rotatable.   
     
     
         5 . The apparatus of  claim 4 , wherein when viewed in a circular cross-section of the apparatus between the support member and the worm wheel, a width between the inner-diameter portion of the worm wheel and each of the first support surface and the second support surface increases from the one end of each of the first support surface and the second support surface toward another end of each of the first support surface and the second support surface, and a width between the inner-diameter portion of the worm wheel and each of the third support surface and the fourth support surface increases from the one end of each of the third support surface and the fourth support surface toward another end of each of the third support surface and the fourth support surface. 
     
     
         6 . The apparatus of  claim 4 , wherein the first roller and the second roller are each configured to be released as the first roller and the second roller are each pushed toward the another end of each of the first support surface and the second support surface by the first coupling protrusion inserted between the first roller and the second roller. 
     
     
         7 . The apparatus of  claim 4 , wherein the third roller and the fourth roller are each configured to be released as the third roller and the fourth roller are each pushed toward the another end of each of the third support surface and the fourth support surface by the second coupling protrusion inserted between the third roller and the fourth roller. 
     
     
         8 . The apparatus of  claim 3 , wherein the support member and the clutch drum are elastically supported by an elastic member disposed between the support member and the clutch drum. 
     
     
         9 . The apparatus of  claim 8 , wherein a shift ring is coupled to an outer-diameter portion of the clutch drum, and
 wherein the shift ring comprises:   a main body having a ring shape and comprising an inner ring portion and an outer ring portion, the inner ring portion being inserted and coupled into a coupling groove positioned on the outer-diameter portion of the clutch drum; and   a cut-out portion positioned between one end and another end of the main body, the one end and the another end of the main body being opposite to each other.   
     
     
         10 . The apparatus of  claim 9 , wherein a coupling pin is coupled to penetrate the one end of the main body, one end of a lever, and the another end of the main body in a state in which the one end of the lever is inserted into the cut-out portion of the main body. 
     
     
         11 . The apparatus of  claim 10 , wherein the elastic member is configured to be compressed when the clutch drum is moved in an engagement direction toward the support member by a force applied to the lever, and the clutch drum is configured to be moved in a disengagement direction by a restoring force of the elastic member when the force applied to the lever is eliminated. 
     
     
         12 . The apparatus of  claim 1 , wherein the worm wheel is connected to a power source by a power transmission member. 
     
     
         13 . The apparatus of  claim 12 , wherein the power transmission member includes a belt, and a gear portion disposed on an inner-diameter portion of the power transmission member is configured to engage with a gear portion disposed on an outer-diameter portion of the worm wheel. 
     
     
         14 . The apparatus of  claim 4 ,
 wherein the first support surface, the second support surface, the third support surface, and the fourth support surface are each a planar surface cutting a round circumferential surface of the outer-diameter portion of the lead nut, the planar surface extending in the longitudinal direction of the lead nut and terminating short of an entire length of the lead nut,   wherein a first stepped projection, a second stepped projection, a third stepped projection, and a fourth stepped projection, which respectively correspond to the first support surface, the second support surface, the third support surface, and the fourth support surface, are defined on portions of the outer-diameter portion of the lead nut where the planar surfaces terminate,   wherein the first locking member is attached to and supported on the first stepped projection, the second locking member is attached to and supported on the second stepped projection, the third locking member is attached to and supported on the third stepped projection, and the fourth locking member is attached to and supported on the fourth stepped projection.   
     
     
         15 . The apparatus of  claim 3 ,
 wherein the first support protrusion includes a first key of the support member positioned on an inner-diameter portion of the first support protrusion, and the second support protrusion includes a second key of the support member positioned on an inner-diameter portion of the second support protrusion,   wherein the at least one key positioned on an inner-diameter portion of the clutch drum includes a first key of the clutch drum and a second key of the clutch drum aligned with the first key of the support member and the second key of the support member, respectively, along the longitudinal direction of the lead nut.   
     
     
         16 . The apparatus of  claim 3 , wherein a width of the first coupling protrusion decreases toward a distal end of the first coupling protrusion, and a width of the second coupling protrusion decreases toward a distal end of the second coupling protrusion. 
     
     
         17 . The apparatus of  claim 16 ,
 wherein a width of the distal end of the first coupling protrusion conforms to a distance between a first roller and a second roller when the first roller and the second roller are fitted between the inner-diameter portion of the worm wheel and the first support surface and the second support surface, respectively, and   wherein a width of the distal end of the second coupling protrusion conforms to a distance between a third roller and a fourth roller when the third roller and the fourth roller are fitted between the inner-diameter portion of the worm wheel and the third support surface and the fourth support surface, respectively.   
     
     
         18 . The apparatus of  claim 3 , wherein when viewed in a circular cross-section of the apparatus between the support member and the worm wheel, the first support surface and the second support surface are symmetrical to each other with respect to a line of symmetry connecting a center of the first coupling protrusion and a center of the second coupling protrusion, and the third support surface and the fourth support surface are symmetrical to each other with respect to the line of symmetry connecting the center of the first coupling protrusion and the center of the second coupling protrusion. 
     
     
         19 . The apparatus of  claim 4 , wherein the first support protrusion is inserted between the first support surface and the third support surface, and the second support protrusion is inserted between the second support surface and the fourth support surface, 
     
     
         20 . The apparatus of  claim 19 ,
 wherein when viewed in a circular cross-section of the apparatus between the support member and the worm wheel,   a width between an end of the first support surface adjacent to the first support protrusion and the inner-diameter portion of the worm wheel is greater than an outer diameter of the first roller,   a width between an end of the second support surface adjacent to the second support protrusion and the inner-diameter portion of the worm wheel is greater than an outer diameter of the second roller,   a width between an end of the third support surface adjacent to the first support protrusion and the inner-diameter portion of the worm wheel is greater than an outer diameter of the third roller,   a width between an end of the fourth support surface adjacent to the second support protrusion and the inner-diameter portion of the worm wheel is greater than an outer diameter of the fourth roller.